Peanut response to co‐inoculation of Bradyrhizobium spp. and Azospirillum brasilense and molybdenum application in sandy soil of the Brazilian Cerrado

Abstract

The use of plant growth–promoting rhizobacteria (PGPR) associated with rhizobia may improve biological N fixation, nutrient acquisition, and grain yield of the peanut (Arachis hypogaea L.). However, few studies have reported the effect of inoculation of rhizobia and PGPR in association with Mo in tropical soil conditions. This study examined the effectiveness of (co)inoculation with Bradyrhizobium spp. and/or Azospirillum brasilense and Mo application in improving the yield response of creeping peanut crop (‘RUNNER IAC 886’). The effects of rhizobacteria and Mo on nodulation, crop growth, chlorophyll content, and yield of peanut were investigated in a moderately acidic sandy soil (pH 5.0) from the Brazilian Cerrado during the 2016–2017 and 2017–2018 growing seasons. Four seed inoculation treatments (control [uninoculated seeds], inoculation with Bradyrhizobium spp. strains SEMIA 5079 and SEMIA 5080, inoculation with Azospirillum brasilense strains Ab‐V5 and Ab‐V6, and co‐inoculation of Bradyrhizobium spp. and Azospirillum brasilense) and two Mo levels (0 and 200 mg Mo kg−1 of seed) were studied. Results showed that the effects of the interaction between rhizobacteria and Mo application were not significant (p > .05) for all crop traits. Root nodulation, dry matter accumulation, and chlorophyll content were significantly greater in Mo‐treated peanut plants than control plants in both seasons. However, the response of crop grain yield was significantly greater (17.7%) in Mo‐treated plants only in the 2017–2018 season. Therefore, the improved root nodulation, crop growth, and chlorophyll content resulting from Mo application can lead to increased pod and grain yield in peanut. Inoculation with Bradyrhizobium spp. alone or combined with A. brasilense enhanced root nodulation, chlorophyll content, and peanut grain yield. Over two harvests, average peanut grain yield increased by 25.3 and 24.0% with inoculation of Bradyrhizobium spp. alone and combined with A. brasilense, respectively, compared with noninoculated plants. Due to lower cost and higher profitability, inoculation of Bradyrhizobium spp. alone is the most efficient practice for peanut cropping in sandy soils of the Brazilian Cerrado. Together with Mo application, these agricultural practices can be recommended for Brazilian peanut farmers.

Co‐inoculation of soybean with Bradyrhizobium spp. and Amazonian strains of Trichoderma asperellum and Bacillus amyloliquefaciens increases the productivity and profitability of the crop

“…The use of sustainable management practices, such as combining different functionalities of promising microorganisms through co‐inoculation, can result in high yields and profitability of agricultural activities (Steiner et al., 2021). Our results show that despite increasing production costs, soybean co‐inoculation provided increases of up to 15.6% in the conventional system (2020) and 21.2% in no‐tillage (2021) in farmers’ profits.…”

Azospirillum brasilense and Solarized Manure on the Production and Phytochemical Quality of Tomato Fruits (Solanum lycopersicum L.)

“…Although nitrates in sap did not reflect a significance with p < 0.05 in the interaction of factors, an effect was identified from proteins in the root and stem, while for lipids the effect was found in the root, stem and leaves (Figure 2 a-e), identifying that, in chlorophyll "b", this interaction was favored for Ab + M40 (Figure 2c). These results can be attributed to the fact that Ab, as a PGPB, tends to make photosynthetic activity more efficient, as well as the chlorophyll content, due to the high levels of CO 2 uptake; therefore, there is a greater accumulation of sugars in the fruits [55][56][57]. The nitrate content in Ab + M (40, 80, 120 and 160) and A + CHF plants for all treatments was very high (without significance) with respect to the plants that were not inoculated with the N 2 -fixing bacteria used in this studio.…”